The Airbus A350 is nearing the start of certification trials
The first entered the preliminary flight-test phase on June 14, and made its much publicized flyover at the Paris air show only one week later. Now the initial part of the flight-test campaign is drawing to a close.
Airbus expects to be able to freeze the final configuration for flap settings in various flight phases, including takeoffs, approaches and landings, within 4-6 weeks. Once the optimum configuration has been determined and validated against simulation data, the manufacturer will have passed a crucial milestone, which heralds the start of the actual certification testing later this year.
MSN001 resumed its test program on Aug. 15 following a planned break in the schedule to allow for more test equipment to be installed. Additional instrumentation was added to measure loads, and more cameras were put onboard. As of last week, the aircraft had logged more than 150 flight hours and was flying almost daily. This amount of test hours is at the upper limit of expectations, according to Airbus officials.
Following the temporary break, the average flight times have regularly exceeded 6-7 hr. When the aircraft made its debut at the Paris air show, that excursion was included in a test flight that exceeded 9 hr.
Last week, Airbus CEO Fabrice Bregier became one of the first non-test crew to fly onboard the A350. The sortie he was on flew close to 4 hr. Not surprisingly, Bregier promptly announced that he liked the smooth ride and was impressed by the large flat-panel screen displays in the cockpit.
Having initially devoted most of the time to open the full flight envelope (all expected speeds and altitudes), MSN001 is now mainly undergoing performance testing at various configurations (flap settings) to determine the best angle for each setting in a trade-off between lift and drag. While most settings will be identical for takeoff and landing, the slats setting in “position flaps 3” will be slightly different, according to Patrick du Che, head of flight-test development. Data generated in the tests is used to run a series of models to determine the optimum configuration.
The minimum unstick speed test, or VMU (velocity of minimum unstick) is planned for mid-month. This highly intense maneuver is used to determine what the lowest speed is at which the aircraft can still take off.
Once the configuration is frozen, performance and certification testing begin in earnest. MSN003, the second A350, due to make its first flight in October, is mainly tasked with the performance and engine testing. Autoland and landing performance trials are set to commence following the freeze. The first realistic figures on fuel burn will become available in that phase, too.
Not all of the current flying is devoted to establishing the right configuration; systems-testing and handling-quality work is also included, particularly when external factors do not allow programs such as climb performance runs. These took place in late August, says Airbus Chief Test Pilot Peter Chandler.
Twenty of Airbus's 28 test pilots have already flown the A350, and the remaining few will have logged at least one A350 flight by the end of the month, when they return from summer vacations.
With MSN003 in place, the program until the end of the year will include engine and performance testing, and all the flutter testing, including those run at the highest speeds.
Icing trials are planned for November and will likely take place in France, given the expected weather conditions. The Dubai Airshow, which opens Nov. 16, might be the first occasion for the A350 to land at an airport outside of Europe.
The A350 will be spending more time abroad for hot-and-high tests. These could still happen before the end of the year or they could shift into early 2014, depending on progress achieved in the other areas. These trials are to take place in South America, possibly in La Paz, Bolivia, although Airbus has not confirmed the site. La Paz has been used for such trials in previous campaigns, including for the-600.
Airbus plans to use a fleet of four aircraft to achieve certification by the middle of 2014. Overall, 2,500 flight hours will have been devoted to the test program.will be the first airline to take delivery of an A350, likely in third-quarter 2014. Airbus holds 682 firm orders for the A350, 448 of which have been placed for the -900 baseline version.